2-D scatter plot with loess estimation of an additional numeric score (levelplot)

This function represents a two dimensional scatter plot with a continuous convex colored surface and/or contour lines representing a third variable.

Usage

s.image(dfxy, z, xax = 1, yax = 2, span = 0.5, gridsize = c(80L, 80L), 
  contour = TRUE, region = TRUE, outsideLimits = NULL, breaks = NULL,
  nclass = 8, col = NULL, facets = NULL, 
  plot = TRUE, storeData = TRUE, add = FALSE, pos = -1, ...)

Arguments

dfxy: a data frame used to produce the plot
z: a vector (or a matrix) of values on the dfxy rows
xax: an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the x-axis
yax: an integer (or a vector) indicating which column(s) of dfxy is(are) plotted on the y-axis
span: a value to control the degree of smoothing
gridsize: a 1 or 2-length vector indicating the cell numbers (horizontally and vertically) of the grid for the colored surface
contour: a logical to draw contour lines
region: a logical to fill inter-contour regions
breaks: a vector of values to split z. If NULL, pretty(z, nclass) is used.
nclass: an integer for the number of desired intervals, ignored if breaks is not missing.
outsideLimits: specific limits for the surface as a set of polygons. It must be an SpatialPolygons object. Hole are authorized.
col: a color or a colors vector used for the colored cells
facets: a factor splitting the rows of dfxy so that subsets of the data are represented on different sub-graphics
plot: a logical indicating if the graphics is displayed
storeData: a logical indicating if the data should be stored in the returned object. If FALSE, only the names of the data arguments are stored
add: a logical. If TRUE, the graphic is superposed to the graphics already plotted in the current device
pos: an integer indicating the position of the environment where the data are stored, relative to the environment where the function is called. Useful only if storeData is FALSE
...: additional graphical parameters (see adegpar and trellis.par.get)

Value

An object of class ADEg (subclass S2.image) or ADEgS (if add is TRUE and/or if facets or multidimensional z or vectors for xax/yax are used).
The result is displayed if plot is TRUE.

Author

Alice Julien-Laferriere, Aurelie Siberchicot aurelie.siberchicot@univ-lyon1.fr and Stephane Dray

Examples

df1 <- data.frame(expand.grid(-3:3, -3:3))
names(df1) <- c("x", "y")
z1 <- (1 / sqrt(2)) * exp(-(df1$x ^ 2 + df1$y ^ 2) / 2)
g1 <- s.image(df1, z1)


# add a continuous color bar as legend
# update(g1, plegend.drawColorKey = TRUE)

g2 <- s.image(df1, z1, gridsize = 50)


g3 <- s.image(df1, z1, gridsize = 100)

## g4 <- s.image(df1, z1, gridsize = 1000, plot = FALSE)

if (FALSE) { # \dontrun{
  if(require(splancs, quietly = TRUE) & require(sp, quietly = TRUE)) {
    Sr1 <- Polygon(cbind(c(0, 1, 2, 1, 2, 0, -2, -1, -2, -1, 0), 
      c(2.5, 1.5, 2, 0, -2, -1, -2, 0, 2, 1.5, 2.5)))
    Sr2 <- Polygon(cbind(c(-0.5, 0.5, 0.5, -0.5, -0.5), c(0, 0, 1 ,1, 0)), hole = TRUE)
    Srs2 <- Polygons(list(Sr1, Sr2), ID = "star and hole")
    SPp <- SpatialPolygons(list(Srs2))
    df2 <- cbind(c(rnorm(2000, 1, 0.25), rnorm(3000, -1, 1.5)), c(rnorm(2000, 1, 0.5), 
      rnorm(3000, -1, 3)))
    z2 <- c(rnorm(2000, 12, 1), rnorm(3000, 1, 2))
    g5 <- s.image(df2, z2, outsideLimits = SPp, grid = 200, xlim = c(-2.5, 2.5), 
      ylim = c(-2, 3), ppalette.quanti = colorRampPalette(c(grey(0.1), grey(0.9))))
  
    data(t3012, package = "ade4")  
    g6 <- s.image(t3012$xy, ade4::scalewt(t3012$temp), porigin.include = FALSE)
    g7 <- s.image(t3012$xy, ade4::scalewt(t3012$temp), outsideLimits = t3012$Spatial, 
      Sp = t3012$Spatial)
  }
} # }